| 摘要 |
1521154 Expanding mandrel for shaping tubes A JOHANSSON 18 June 1976 [23 June 1975] 25458/76 Heading B5A The softened end of a tube is deformed by a mandrel 2 having an expandible and retractible portion 10 (as shown for producing a groove) comprising two groups of alternating segments, each groove being expanded and retracted with respect to the mandrel body by separate mechanism. In Fig. 1, each of one group of segments is moved by a respective rod 14 operated by a plate 7, shaft 5 and piston/ cylinder. The other group are moved by respective rods 18, plate 8, shaft 6 and piston/cylinder In Fig. 5, pressure fluid fed through channels 23 moves the two segment groups 17"/21" in manner equivalent to Fig. 1, with return effected by suction and springs. The segments 17" are tapered (here stepped) to receive the segments 21" when retracted, and are expanded before the smaller segments 21". Coolant or heating fluid flows through channels 31. The tube is heated and placed on the mandrel before or after segment expansion, and is sucked on to the moulding surface. |
